首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   412篇
  免费   0篇
安全科学   6篇
废物处理   51篇
环保管理   27篇
综合类   20篇
基础理论   48篇
环境理论   1篇
污染及防治   114篇
评价与监测   118篇
社会与环境   24篇
灾害及防治   3篇
  2023年   20篇
  2022年   34篇
  2021年   22篇
  2020年   5篇
  2019年   9篇
  2018年   23篇
  2017年   14篇
  2016年   26篇
  2015年   10篇
  2014年   25篇
  2013年   38篇
  2012年   9篇
  2011年   12篇
  2010年   29篇
  2009年   31篇
  2008年   27篇
  2007年   17篇
  2006年   7篇
  2005年   6篇
  2004年   5篇
  2003年   13篇
  2002年   11篇
  2001年   5篇
  2000年   4篇
  1998年   1篇
  1997年   3篇
  1996年   1篇
  1993年   1篇
  1990年   1篇
  1984年   1篇
  1979年   1篇
  1973年   1篇
排序方式: 共有412条查询结果,搜索用时 50 毫秒
361.
Endocrine-disrupting compounds (EDCs) are exogenous substances that cause adverse health effects in an intact organism, or its progeny, subsequent to the changes in endocrine function. Recent studies have shown that wastewater treatment plant effluents play an important role in the release of EDCs into aquatic environments. Therefore, in this study, influent and effluent samples from three different wastewater treatment plants (WWTPs) in Istanbul were analysed for the presence of the principal EDCs. These chemicals include steroids and synthetic organic chemicals. Thus, the occurrence and fate of EDCs of great health concern were monitored at three WWTPs in Istanbul. Furthermore, these WWTPs are employing different treatment processes. Therefore, the EDC removal performances of different treatment regimes were also evaluated. Phytosterol was the most abundant EDC in the influent samples. Second group of compounds at high influent levels were alkyl phenols. Pesticide levels of all three WWTP influent samples were low. Pasakoy Advanced WWTP is more effective at eliminating EDCs. Kadikoy Primary WWTP exhibits the lowest EDC elimination efficiencies. To the best of our knowledge, this work comprises the first detailed report on the occurrence and behaviour of both natural and synthetic EDCs in WWTPs of Istanbul and Turkey. The steroid estrogen levels of this study are higher than the previously documented values, except the levels given for Gaobeidian WWTP in Beijing, China. This is attributed to higher population densities of Beijing and Istanbul and as well as to lower individual water consumption rates in the two cities.  相似文献   
362.
Capture-based aquaculture of Atlantic bluefin tuna in the Mediterranean has been expanding rapidly but little is known about its environmental impact. In order to understand the consequences of this new sector, long-term monitoring is needed. For this purpose, we investigated the impact of a capture-based tuna farm located in the Gerence Bay (Aegean Sea) on the water column on a seasonal basis from 2005 to 2008, where in the water column, temperature, salinity, pH, dissolved oxygen, nutrients (nitrite, nitrate, ammonium, and phosphate), and chlorophyll a, in the sediment organic carbon variables were measured. Although highest nutrient concentrations were observed at the cage station as compared to the two controls in the production period, differences were not statistically significant between stations. Monitoring of physico-chemical parameters, nutrients, and chlorophyll a in water column together with organic carbon in sediment did not show detectable impact of fattening of Atlantic bluefin tuna. This was probably caused by strong currents present in the area, location of the cages away from the coast, hence high water depth, controlled feeding, and periodic presence of tuna farming activity in the study area.  相似文献   
363.
364.
Amisulbrom formulated as suspension concentrate was applied at the rate recommended for Korean melon to determine the dissipation pattern (at two different sites), the pre-harvest residue limit (PHRL), and risk assessments. Samples collected over 10 days were extracted using liquid-liquid extraction (LLE) and cleaned up with solid-phase extraction (SPE) Florisil cartridge. Residual concentrations were determined using liquid chromatography-ultraviolet detector (LC-UVD) and confirmed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The standard showed good instrument response linearity with a correlation coefficient (R 2) = 0.9999, and the recovery ranged from 87.5 to 93.7%. The dissipation half-life calculated from two different sites were found to be 7.0 and 8.8 days for sites 1 and 2, respectively. A PHRL graph constructed from the data indicated that if the residue levels were less than 0.55–0.59 mg/kg 3 days before harvest or less than 0.61–0.74 mg/kg 7 days before harvest, then they would be lower than the maximum residue limits (MRLs) at harvest. Risk assessments showed that the risk quotient (RQ) was 4.39–3.47% at 0 day, declined to 1.53–1.63% at 10 days. Therefore, the current data indicate that the amisulbrom can be applied safely to Korean melon; hence, it is unlikely to induce adverse health effects in consumers.  相似文献   
365.
The diversity of forest trees as an indicator of ecosystem health can be assessed using the spectral characteristics of plant communities through remote sensing data. The objectives of this study were to investigate alpha and beta tree diversity using Landsat data for six dates in the Gönen dam watershed of Turkey. We used richness and the Shannon and Simpson diversity indices to calculate tree alpha diversity. We also represented the relationship between beta diversity and remotely sensed data using species composition similarity and spectral distance similarity of sampling plots via quantile regression. A total of 99 sampling units, each 20 m × 20 m, were selected using geographically stratified random sampling method. Within each plot, the tree species were identified, and all of the trees with a diameter at breast height (dbh) larger than 7 cm were measured. Presence/absence and abundance data (tree species number and tree species basal area) of tree species were used to determine the relationship between richness and the Shannon and Simpson diversity indices, which were computed with ground field data, and spectral variables derived (2 × 2 pixels and 3 × 3 pixels) from Landsat 8 OLI data. The Shannon-Weiner index had the highest correlation. For all six dates, NDVI (normalized difference vegetation index) was the spectral variable most strongly correlated with the Shannon index and the tree diversity variables. The Ratio of green to red (VI) was the spectral variable least correlated with the tree diversity variables and the Shannon basal area. In both beta diversity curves, the slope of the OLS regression was low, while in the upper quantile, it was approximately twice the lower quantiles. The Jaccard index is closed to one with little difference in both two beta diversity approaches. This result is due to increasing the similarity between the sampling plots when they are located close to each other. The intercept differences between two investigated beta diversity were strongly related to the development stage of a number of sampling plots in the tree species basal area method. To obtain beta diversity, the tree basal area method indicates better result than the tree species number method at representing similarity of regions which are located close together. In conclusion, NDVI is helpful for estimating the alpha diversity of trees over large areas when the vegetation is at the maximum growing season. Beta diversity could be obtained with the spectral heterogeneity of Landsat data. Future tree diversity studies using remote sensing data should select data sets when vegetation is at the maximum growing season. Also, forest tree diversity investigations can be identified by using higher-resolution remote sensing data such as ESA Sentinel 2 data which is freely available since June 2015.  相似文献   
366.
Environmental and Ecological Statistics - The paper investigates the non-linear causality from energy consumption and economic growth to ecological footprint for the case of Turkey by employing...  相似文献   
367.
The cadmium and copper levels were determined in the total of 126 fish samples which belongs to five fish species collected from Sır and Menzelet Dam Lakes in Kahramanmaraş Province by Atomic Absorption Spectrophotometer. The concentrations of heavy metals were expressed as ppm wet weight of tissue. The mean levels of cadmium and copper in muscle, liver and gill tissues of Cyprinus carpiofrom the Menzelet Dam were found as 0.27, 0.91, 1.49 and 0.94, 1.2, 1.05, respectively. The mean levels of Cd in the muscle tissues of Leuciscus cephalusfrom the Menzelet Dam were found 0.32 ppm, Cd wasn't found in tissues of liver and gill. The mean levels of Cu in the muscle, liver and gill tissues were found as 3.17 ppm, 1.19 ppm, 0.96 ppm, respectively. The mean levels of the Cd and Cu in muscle and gill tissues of Acanthobrama marmid from the Sır Dam were found as 1.28, 2.64 and 0.72, 0.08, respectively. The levels of the Cd and Cu in muscle tissues of Cyprinus carpiofrom the Sır Dam were found 0.87 and 0.02 ppm, respectively. The mean levels of the Cd and Cu in the muscle and gill tissues of Chondrostoma regium from the Sır Dam were found to be 0.80, 2.62 and 0.67, 1.34 ppm, respectively. The mean levels of the Cd in the muscle tissues of the Silurus glanis was found as 0.60 ppm. In the muscle of the Silurus glanis from the Sır Dam, Cu was not found. The Sır Dam is more polluted than the Menzelet Dam from the point of Cd but less polluted than the Menzelet Dam From the point of Cu. A relationship was determined between species and their habitating region in terms of the levels reflected metal residues. In this study it was emphasized that the amounts of Cd and Cu in the samples were low, however, seas, lakes, rivers, soil, air and consumed foods etc. has to be controlled routinely.  相似文献   
368.
The aim of this study is to evaluate extensively the characterization and identification of major pollutant parameters by paying attention to the organic chemical pollution for unregulated dumping site leachate in Eskişehir/Turkey. The study that is first and only one research has been very important data related with before new sanitary landfill site in Eskişehir city. For this purpose, in this study leachate samples were collected in-situ at monthly interval for a period of 8 months. Firstly, thirty three physicochemical parameters were monitored. Secondly, SPME technique was used for identification of organic pollutants. Meteorological data were also recorded for the same sampling period to correlate meteorological data and physicochemical parameters. Mean values are used in the correlation analysis. Correlation is shown only for the relationship between air temperature and NO3 . No correlation has been found between rain and leachate quality parameters since the amount of rain was very low during the sampling period. However, analysis results were generally decreased in winter season when each parameter and each sampling point are examined separately. According to correlation between every parameter, especially solid content and dissolved oxygen concentration of leachate is affecting to other parameters. Also, sodium and potassium are changing proportionally with same parameters (suspended solids, fixed solids, dissolved oxygen) and high correlation between chloride and heavy metal concentration is showing. The results were statistically evaluated by use of SPSS 10.0 program. Second part of the study, the leachate was extracted by Solid Phase Microextraction (SPME) technique and then analyzed. Of the methodologies tested in this study, the best one selected was based on 100 μ m polydimethylsiloxane coated fiber (PDMS), headspace with heating (Δ HS) sampling mode and an extraction time of 15 min. at a temperature of 50 o C. Thirty three organic compounds in leachate were identified by GC/MS.  相似文献   
369.
Metal Concentrations in Fish Species from the Northeast Mediterranean Sea   总被引:3,自引:0,他引:3  
Samples of Mugil cephalus and Mullus barbatus were collected in the Northeast Mediterranean coast of Turkey the contents of cadmium, copper, iron, zinc and lead in the liver, gill and muscle tissues were determined by atomic absorption flame spectrophotometry.Except for lead, highest levels of each metal were found in the liver and this was followed by the gill and muscle in both species. Among the metals analyzed, Cu, Zn and Fe were the most abundant in the different tissues while Cd and Pb were the least abundant both in M. cephalus and M. barbatus. Seasonal changes in metal (Cd, Cu, Pb, Fe and Zn) concentration were observed in the tissues of both species, but these seasonal variations may not influence consumption advisories. In general, the highest concentrations were detected for all metals in summer.  相似文献   
370.
Journal of Material Cycles and Waste Management - One of the most significant environmental problems the world population faces is the inadequate disposal of petroleum derivatives. Lubricant oil is...  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号